This invention is generally directed to imaging members, and more specifically, the present invention is directed to photoconductive imaging members with a hole blocking, or undercoat layer (UCL) generated, for example, from a solution, particularly a homogenous solution, of a titanium alkyloxide, such as titanium isopropoxide, a triaminoalkyl alkoxy silane like 3-aminopropyl trimethoxysilane (APS), a polymer binder, such as poly(methyl methacrylate) (PMMA), vinyl chloride copolymer and poly(vinyl butyral) (PVB) thereof, and a suitable solvent like a ketone, such as methyl ethyl ketone, and an alcohol, such as 1-propanol, which solution in embodiments is transparent and wherein the solvent, the titanium compound and the silane can form, for example, titanates, such as ammonium titanates, in an acidic environment. More specifically, the hole blocking layer in contact with the supporting substrate can be situated between the supporting substrate and the photogenerating layer, which is comprised, for example, of the photogenerating pigments of U.S. Pat. No. 5,482,811, the disclosure of which is totally incorporated herein by reference, especially Type V hydroxygallium phthalocyanine, and generally metal free phthalocyanines, metal phthalocyanines, perylenes, titanyl phthalocyanines, seleniums, selenium alloys, azo pigments, squaraines, and the like. The imaging members of the present invention in embodiments exhibit excellent and stable electrical characteristics; cyclic/environmental stability, and substantially no adverse changes in their performance over extended time periods since, for example, the imaging members comprise a mechanically robust and solvent resistant hole blocking layer, enabling the coating of a subsequent photogenerating layer thereon without substantial structural damage; low and excellent Vlow, that is the surface potential of the imaging member subsequent to a certain light exposure, and which Vlow is about 20 to about 75 volts lower than, for example, a comparable hole blocking layer of a titanium oxide/phenol resin/silicon oxide dopant, and which blocking layer can be easily coated on the supporting substrate by various coating techniques of, for example, dip or slot-coating. The photoresponsive, or photoconductive imaging members can be negatively charged when the photogenerating layers are situated between the hole transport layer and the hole blocking layer deposited on the substrate.
Processes of imaging, especially xerographic imaging, and printing, including digital, are also encompassed by the present disclosure. More specifically, the layered photoconductive imaging members of the present disclosure can be selected for a number of different known imaging and printing processes including, for example, electrophotographic imaging processes, especially xerographic imaging and printing processes wherein charged latent images are rendered visible with toner compositions of an appropriate charge polarity. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 500 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this invention are useful in color xerographic applications, particularly high-speed color copying and printing processes.